Effect of elastase inhibitor on the homing of AML and normal progenitor cells. Primary human AML MNCs from 8 patients, either untreated or after 30 minutes of incubation with EI (10 μg/mL), were injected into sublethally irradiated NOD/SCID/B2mnull mice. (A) Data show the percentage of human CD45⁺ cells present in the murine BM compared with control (100%). Statistical significance of inhibition from the 8 samples taken together was P = .05. Experiment with cells from patients no. 16 and no. 21 was done in duplicate, and results show mean ± SE. (B) Representative FACS plot. A mouse that was not injected is shown as control (non-inj.). (C) Comparison of the effect of EI (10 μg/mL) on the homing of CD34⁺ cells derived from normal CB and primary AML (M4E, no. 8 and M4, no. 16) cells. Data show the percentage of human CD45⁺ cells present in the murine BM compared with control (100%). Results are average ± SE of 3 independent experiments; ^*P ≤ .05.